Device for exchange of energy and/or mass transfer between fluid flows

ABSTRACT

The present disclosure relates to a device for exchange of energy and/or mass transfer between fluid flows, which device comprises a first fluid inlet ( 3   a ), a first fluid outlet ( 3   c ), a second fluid inlet ( 5   a ), a second fluid outlet ( 5   c ), a plurality of first channel layers ( 3 ) connecting the first fluid inlet ( 3   a ) with the first fluid outlet ( 3   c ), and a plurality of second channel layers ( 5 ) connecting the second fluid inlet ( 5   a ) with the second fluid outlet ( 5   c ), wherein the plurality of first channel layers ( 3 ) and the plurality of second channel layers ( 5 ) are arranged in a stacked manner forming stacked fluid channels ( 2 ), wherein at least some of the first channel layers ( 3 ) are in physical contact with a respective second channel layer ( 5 ) thereby forming channel pairs, wherein the channel pairs are spaced apart from each other, whereby cross-current channels ( 7 ) are formed therebetween, extending from one lateral side ( 9 ) of the stacked fluid channels ( 2 ) to the opposite lateral side ( 11 ) of the stacked fluid channels ( 2 ), thereby forming lateral fluid inlets ( 13 ) between lateral edges of first channel layers ( 3 ) and second channel layers ( 5 ) and lateral fluid outlets between opposite lateral edges of first channel layers ( 3 ) and second channel layers ( 5 ).

TECHNICAL FIELD

The present disclosure generally relates to the exchange of energy ormass transfer between fluid flows.

BACKGROUND

Conventional heat exchangers are always problematic to use in coldclimate because the risk of freezing. This is because condensation wateris accumulated inside the heat exchanger, which freezes when thetemperature plummets below about −4° C.

The more efficient a heat exchanger is the greater is the problem offreezing, especially for counterflow heat exchangers.

SUMMARY

In view of the above, a general objective of the present disclosure isto provide a device for exchange of energy and/or mass transfer which atleast mitigate the problems of the prior art.

There is hence provided a device for exchange of energy and/or masstransfer between fluid flows, which device comprises a first fluidinlet, a first fluid outlet, a second fluid inlet, a second fluidoutlet, a plurality of first channel layers connecting the first fluidinlet with the first fluid outlet, and a plurality of second channellayers connecting the second fluid inlet with the second fluid outlet,wherein the plurality of first channel layers and the plurality ofsecond channel layers are arranged in a stacked manner forming stackedfluid channels, wherein at least some of the first channel layers are inphysical contact with a respective second channel layer thereby formingchannel pairs, wherein the channel pairs are spaced apart from eachother, whereby cross-current channels are formed therebetween, extendingfrom one lateral side of the stacked fluid channels to the oppositelateral side of the stacked fluid channels, thereby forming lateralfluid inlets between lateral edges of first channel layers and secondchannel layers and lateral fluid outlets between opposite lateral edgesof first channel layers and second channel layers.

This configuration enables a multitude of different uses of the device.The device may for example be used as a heat exchanger withcounter-current flow in the first channel layers and the second channellayers, and a cross-current flow in the cross-current channels. Thishybrid set-up provides a great plurality of different applications; itallows for example a three-fluid set-up or a dual fluid set-up where thecounter-current flow is provided from the same fluid source as the crosscurrent flow.

The first channel layers, the second channel layers and thecross-current channels are thus arranged so that they provide fluidflows in planes parallel to each other. For example, as mentioned above,the first channel layers and the second channel layers may providecounter-current flows, and the cross-current channels may provide across-current flow with respect to the flows in the first channel layersand the second channel layers.

In this case, there will be a heat exchange and/or mass transfer betweenthe counter- (or con-) current flows in the channel pair in addition toa “main” heat exchange and/or mass transfer between the cross-currentflow and the counter- (or con-) current flows. In case both the firstfluid inlet and the second fluid inlet are connected to the same fluidsource there will be an automatic flow regulation in the channels of thefirst channel layers and second channel layers. For example, in freezingtemperatures, in case one of the channels is in the process of freezing,the additional flow resistance created in this channel by ice formationwill lead to a corresponding higher flow rate in the remaining channels.In this application this will result in a re-distribution of fluid flowcreating a higher flow of warm air e.g. exhaust air from a buildingthrough the remaining channels. This would in turn heat these channelsto such an extent that the device could be used in lower temperaturesthan existing devices of this type, where the channels would freeze at ahigher temperature than what can be obtained by the device of thepresent disclosure. In particular, this would allow a serial procedureof channels freezing, compared to existing solutions where all channelsfreeze essentially simultaneously.

The device for exchange of energy and/or mass transfer between fluidflows may be a device for exchange of heat and/or mass transfer betweenfluid flow.

According to one embodiment a cross-current channel is arranged betweeneach channel pair.

According to one embodiment the cross-sectional area of any channel ofthe first channel layers is greater than a cross-sectional area of anychannel of the second channel layers. The cross-sectional dimension ofthe channels may hence be designed such that the fluid flows can bedifferentiated. The order in which the channels of the first channellayers and the second channel layers freeze may thereby be determined.The different cross-sectional dimensions may also be a design-parameterwhen determining the types of fluid that are to flow through the firstchannel layers and the second channel layers, respectively. A liquidfluid may for example store much more energy than a gas. The fluid whichis able to store the most energy may thus for example be routed to flowthrough the channels with a smaller cross-sectional area.

According to one embodiment the first fluid inlet and the second fluidoutlet form a first fluid interface arranged at a first end of the firstchannel layers and second channel layers.

According to one embodiment the first fluid interface istriangular-shaped in a plane parallel with a first channel layer.

According to one embodiment the first fluid outlet and the second fluidinlet form a second fluid interface arranged at a second end of thefirst channel layers and second channel layers, opposite to the firstend.

According to one embodiment each first channel layer comprises aplurality of parallel channels and each second channel layer comprises aplurality of parallel channels.

According to one embodiment the parallel channels of the first channellayers are arranged in parallel with the parallel channels of the secondchannel layers.

According to one embodiment the first fluid inlet and the second fluidinlet are arranged at a first end and a second end, respectively, of thestacked fluid channels, the first end and the second end being oppositeends of the stacked fluid channels, and wherein the first fluid outletis arranged at the second end and the second fluid outlet is arranged atthe first end.

One embodiment comprises a fluid conduit extending through each of theplurality of first channel layers and each of the plurality of secondchannel layers.

According to one embodiment the fluid conduit extends a plurality oftimes through each of the plurality of first channel layers and each ofthe plurality of second channel layers.

According to one embodiment each first channel layer is made of twosheets and each second channel layer is made of two sheets, wherein eachsecond channel layer shares a sheet with a second channel layer therebyforming the channel pair.

According to one embodiment the device is a fuel cell.

According to a second aspect of the present disclosure there is provideda device for exchange of heat and/or mass transfer between fluid flows,which device comprises: a first fluid inlet, a first fluid outlet, aplurality of first channel layers connecting the first fluid inlet withthe first fluid outlet, the plurality of first channel layers beingarranged in a stacked manner forming stacked fluid channels, and a fluidconduit extending through each of the plurality of first channel layers,wherein at least some first channel layers are spaced apart from eachother, whereby cross-current channels are formed therebetween, extendingfrom one lateral side of the stacked fluid channels to the oppositelateral side of the fluid channels, thereby forming lateral fluid inletsbetween lateral edges of first channel layers and lateral fluid outletsbetween opposite lateral edges of first channel layers, and wherein thefluid conduit extends through each cross-current channel.

The device could hence be described as a type of tube and fin heatexchanger, however with multiple flow paths arranged to providedifferentiated heat exchange with the fluid conduit. This reduces therisk of simultaneous frost formation in first channel layers and thecross-current channels.

According to one embodiment the fluid conduit extends a plurality oftimes through each of the plurality of first channel layers and each ofthe plurality of cross-current channels. The fluid conduit thusintersects each first channel layer a plurality of times, and eachcross-current channel a plurality of times.

The fluid conduit hence intersects each first channel layer andcross-current channel, wherein when having exited the stacked fluidchannels the fluid conduit is bent back and led through the stackedfluid channels again. This is repeated a plurality of times.

The fluid conduit hence forms a cooling coil or a heating coil. Thefluid conduit is typically a tube.

The fluid conduit should be manufactured by a material with good heatconducting characteristics, for example a metal, e.g. copper, or aheat-conducting plastic material, e.g. plastic mixed with a metalpowder.

In a typical embodiment a liquid is arranged to flow through the fluidconduit, for example a refrigerant.

The device could also, according to some embodiments, comprise more thanone fluid conduits of the type described above.

One embodiment comprises a second fluid inlet, a second fluid outlet, aplurality of second channel layers connecting the second fluid inletwith the second fluid outlet, wherein the plurality of first channellayers and the plurality of second channel layers are arranged in astacked manner forming the stacked fluid channels, and a fluid conduitextending through each of the plurality of first channel layers and eachof the plurality of second channel layers wherein at least some firstchannel layers are spaced apart from second channel layers, wherebycross-current channels are formed therebetween, extending from onelateral side of the stacked fluid channels to the opposite lateral sideof the fluid channels, thereby forming lateral fluid inlets betweenlateral edges of first channel layers and second channel layers andlateral fluid outlets between opposite lateral edges of first channellayers and second channel layers.

According to one embodiment the fluid conduit extends a plurality oftimes through each of the plurality of first channel layers and each ofthe plurality of second channel layers.

According to one embodiment the first fluid inlet and the second fluidoutlet form a first fluid interface arranged at a first end of the firstchannel layers and second channel layers.

According to one embodiment the first fluid interface istriangular-shaped in a plane parallel with a first channel layer.

According to one embodiment the first fluid interface forms an isoscelestriangle.

According to one embodiment the first fluid outlet and the second fluidinlet form a second fluid interface arranged at a second end of thefirst channel layers and second channel layers, opposite to the firstend.

According to one embodiment the second fluid inlet and the second fluidoutlet form a first fluid interface arranged at a first end of the firstchannel layers and second channel layers.

According to one embodiment the second fluid interface forms anisosceles triangle.

According to one embodiment each first channel layer comprises aplurality of parallel channels and each second channel layer comprises aplurality of parallel channels.

According to one embodiment the parallel channels of the first channellayers are arranged in parallel with the parallel channels of the secondchannel layers.

According to one embodiment the first fluid inlet and the second fluidinlet are arranged at a first end and a second end, respectively, of thestacked fluid channels, the first end and the second end being oppositeends of the stacked fluid channels, and wherein the first fluid outletis arranged at the second end and the second fluid outlet is arranged atthe first end. Generally, all terms used in the claims are to beinterpreted according to their ordinary meaning in the technical field,unless explicitly defined otherwise herein.

All references to “a/an/the element, apparatus, component, means, etc.are to be interpreted openly as referring to at least one instance ofthe element, apparatus, component, means, etc., unless explicitly statedotherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

The specific embodiments of the inventive concept will now be described,by way of example, with reference to the accompanying drawings, inwhich:

FIG. 1 depicts a perspective view of an example of a device for exchangeof heat and/or mass transfer;

FIG. 2a shows a top view of the device in FIG. 1 in a first mode ofoperation;

FIG. 2b shows a top view of the device in FIG. 1 in a second mode ofoperation;

FIG. 3 is cross-sectional view of some of the first channel layers andsecond channel layers of the device in FIG. 1;

FIGS. 4a-4d show cross-sectional views of some first channel layers andsecond channel layers of different variations of the device in FIG. 1;

FIGS. 5a-b shows another example of a device for exchange of heat and/ormass transfer; and

FIGS. 6a-b show another aspect of a device for exchange of heat and/ormass transfer.

DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter withreference to the accompanying drawings, in which exemplifyingembodiments are shown. The inventive concept may, however, be embodiedin many different forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided byway of example so that this disclosure will be thorough and complete,and will fully convey the scope of the inventive concept to thoseskilled in the art. Like numbers refer to like elements throughout thedescription.

This disclosure relates to a device for exchange of energy such as heator electrons and/or mass transfer between fluids. The device is inparticular a hybrid device in that it allows for example counterflow orconcurrent flow together with a cross-current flow; it is amultiple-path energy and/or mass exchange unit. The device is hence ableto provide heat and/or mass transfer between at least three simultaneousfluid flows.

According to a first aspect, the device comprises a first fluid inlet, afirst fluid outlet, a second fluid inlet and a second fluid outlet.Moreover, the device has a plurality of first channel layers connectingthe first fluid inlet with the first fluid outlet, and a plurality ofsecond channel layers connecting the second fluid inlet with the secondfluid outlet.

Each first channel layer may for example be made of two corrugatedsheets joined together. Each such first channel layer may comprise aplurality of parallel channels. Alternatively, each first channel layermay be formed of two plates whereby the device forms a plate heatexchanger, e.g. a gasket plate heat exchanger.

Each second channel layer may for example be made of two corrugatedsheets joined together. Each such second channel layer may comprise aplurality of parallel channels. Alternatively, each second channel layermay be formed of two plates whereby the device forms a plate heatexchanger e.g. a gasket plate heat exchanger.

The plurality of first channel layers and the plurality of secondchannel layers are arranged in a stacked manner forming stacked fluidchannels.

At least some, and preferably all, of the first channel layers andsecond channel layers are arranged in pairs, in physical contact witheach other thus forming channel pairs. The channel pairs are spacedapart from each other, whereby cross-current channels are formedtherebetween, extending from one lateral side of the stacked fluidchannels to the opposite lateral side of the fluid channels. By lateralside is here meant those sides that are parallel with the general fluidflow direction in the channel layers, i.e. fluid inlet to fluid outletdirection. Lateral fluid inlets are thereby formed between lateral edgesof first channel layers and second channel layers and lateral fluidoutlets between opposite lateral edges of first channel layers andsecond channel layers.

FIG. 1 shows an example of a device 1 for heat exchange and/or masstransfer between fluid flows. The exemplified device 1 comprises aplurality of first channel layers 3 and a plurality of second channellayers 5 stacked on top of each other forming a plurality of stackedfluid channels 2.

The device 1 furthermore comprises a first fluid inlet 3 a and a firstfluid outlet 3 c. According to the example, the first fluid inlet 3 acomprises a plurality of inlet openings 3 b, each being connected to arespective first channel layer 3. The first fluid outlet 3 c may alsocomprise a plurality of outlet openings, each being connected to arespective first channel layer 3. The first channel layers 3 henceconnect the first fluid inlet 3 a with the first fluid outlet 3 c.

The device 1 comprises a second fluid inlet 5 a and a second fluidoutlet 5 c. According to the example, the second fluid inlet 5 acomprises a plurality of inlet openings 5 b, each being connected to arespective second channel layer 5. The second fluid outlet 5 c may alsocomprise a plurality of outlet openings, each being connected to arespective second channel layer 5. The second channel layers 5 henceconnect the second fluid inlet 5 a with the second fluid outlet 5 c.

According to the example shown in FIG. 1, the first channel layers 3 andthe second channel layers 5 are arranged alternatingly in a stackedmanner. The first channel layers 3 and the second channel layers 5 arearranged in pairs, forming channel pairs. Each first channel layer 3 andsecond channel layer 5 that form a channel pair are in physical contactwith each other. This means that there will be a heat and/or masstransfer between the channel layers forming each channel pair. Moreover,there is also a heat and/or mass transfer between channel pairs andcross-current channels.

The channel pairs are spaced apart from each other in this stack. Thereis hence a distance between some first channel layers 3 and secondchannel layers 5, whereby cross-current channels 7 are formedtherebetween. The cross-current channels 7 extend from one lateral side9 of the stacked fluid channels to the opposite lateral side 11 of thestacked fluid channels. Lateral fluid inlets 13 are thereby formedbetween lateral edges of first channel layers 3 and second channellayers 5 and lateral fluid outlets are formed between opposite lateraledges of first channel layers 3 and second channel layers 5. It shouldbe noted that the lateral fluid inlets 13 may also function as lateralfluid outlets and the lateral fluid outlets may also function as lateralfluid inlets; it merely depends on from which of two directions fluidflow is taken into the cross-current channels 7.

The flow direction provided by the cross-current channels 7 are at rightangle with the general flow direction in the channel or channels of thefirst channel layer 3 and the second channel layer 5. They hence providea cross-current fluid flow direction relative to the flow directionsprovided by the first channel layers 3 and the second channel layers 5.

According to the example in FIG. 1 each first channel layer 3 comprisesa plurality of parallel channels and each second channel layer 5comprises a plurality of parallel channels. The parallel channels of thefirst channel layers 3 are arranged in parallel with the parallelchannels of the second channel layers 5. Moreover, according to thisexample, the first fluid inlet 3 a and the second fluid inlet 5 a arearranged at a first end and a second end, respectively, of the stackedfluid channels 2. The first end and the second end are opposite ends ofthe stacked fluid channels 2. The first fluid outlet 3 c is arranged atthe second end and the second fluid outlet 5 c is arranged at the firstend.

Moreover, according to the example in FIG. 1 the first fluid inlet 3 aand the second fluid outlet 5 c form a first fluid interface arranged ata first end of the first channel layers 3 and second channel layers 5,i.e. at the first end of the stacked fluid channels 2. The first fluidinterface can for example be triangular-shaped in a plane parallel witha first channel layer 3. The first fluid interface may for example forman isosceles triangle in this plane.

The first fluid outlet 3 c and the second fluid inlet 5 a form a secondfluid interface arranged at a second end of the first channel layers andsecond channel layers, opposite to the first end, i.e. at the second endof the stacked fluid channels 2. The second fluid interface can forexample be triangular-shaped in a plane parallel with a first channellayer 3. The second fluid interface may for example form an isoscelestriangle in this plane.

FIG. 2a shows a top view of the device 1. Three different fluid flowsF1, F2 and F3 are also illustrated. According to the mode of use shownin FIG. 2a the device 1 is used as a counterflow and cross-current flowdevice. A first fluid flow F1 enters through the first fluid inlet 3 a,flows through the channels of the first channel layers 3 and exitsthrough the first fluid outlet 3 c. A second fluid flow F2 entersthrough the second fluid inlet 5 a, flows through the channels of thesecond channel layers 5 and exits through the second fluid outlet 5 c.Moreover, a third fluid flow F3 is provided as a cross-current flowrelative to the first fluid flow F1 and the second fluid flow F2. Thethird fluid flow F3 enters the stacked fluid channels 2 through thelateral fluid inlets 13 and exits on the opposite side, through thelateral fluid outlets 15.

This operation of the device 1 is especially advantageous in coldweather when there is a risk of freezing in the device 1. The design ofthe device 1 has been shown to be able to operate at in temperaturessignificantly below conventional heat exchangers, where freezing occursat approximately −4° C. This eliminates the need of auxiliary heatersuntil much lower temperatures. The effect can be obtained for example byletting all three fluid flows F1-F3 be air, with the first fluid flow F1and the second fluid flow F2 being exhaust air. Because of the internalheat exchange between first channel layers 3 and second channel layers 5in physical contact with each other and forming channel pairs, freezinginside the channels may be prevented until much lower temperatures thanwould be possible today, without utilising auxiliary heaters. Suchoperation is especially advantageous in cold climate, but a trade-off isthat heat exchange, i.e. heat exchange with the third fluid flow F3,becomes less efficient than in conventional heat exchangers. This canhowever be solved by operating the device 1 differently in warmerclimate, as shown in FIG. 2 b, where the first channel layers 3 andsecond channel layers 5 are operated in concurrent fluid flow mode.Here, the second fluid inlet 5 a and second fluid outlet 5 c havechanged function; the second fluid outlet 5 c is in this case used forfluid intake of the second fluid flow F2. This operation can for examplebe ensured by an aggregate connected to the device 1, which aggregatecomprises draught valves arranged to direct the fluid flow direction.The device 1 may hence be operated in different modes depending on theseason.

FIG. 3 shows a cross-section of the stacked fluid channels 2 in thedirection of the channels i.e. along the first fluid flow F1 and secondfluid flow F2 shown in FIG. 2a for example. The first fluid flow F1 andthe second fluid flow F2 is in this figure in a respective directioninto and out from the illustration. The first channel layers 3 aremarked with a chequered pattern and the second channel layers 5 aremarked with a dashed slanting pattern. The cross-current channels 7 areleft white. The third fluid flow F3 is shown flowing from left to right,inside a respective cross-current channel 7, and perpendicular to thefirst fluid flow F1 and the second fluid flow F2.

FIGS. 4a to 4c show other examples of how first channel layers 3, thesecond channel layers 5 and cross-current channels 7 may be arranged.The first channel layers and second channel layers are also here markedwith chequered pattern and dashed pattern, respectively.

As can be seen, according to these variations, the cross-sectional areaof any channel of the first channel layers 3 is greater than across-sectional area of any channel of the second channel layers 5.Variations in which all channels have the same cross-section are howeveralso envisaged.

FIG. 4d shows another variation, in which there are first channel layers3, second channel layers 5 and first channel layers 3 formed in tripletsin physical contact with each other, and distanced from another suchtriplet by a cross-current channel 7.

In general, it may be noted that there may be more than three fluidflows provided in a device according to the present disclosure. This isdependent of the number of channel layers and corresponding fluid inletsand outlets provided.

As an example, in FIG. 4 d, first channel layers 3, may be provided witha flow of water at 4° C., second channel layers, 5, may be provided witha flow of hot water from district heating at e.g. 120° C., third layerse.g. the cross-current channels may be provided with supply air, andfourth channel layers 4, may be provided with hot water supply from abuilding's heating recirculation system. The district heating waterheats the water in the first channel layers and the fourth channellayers to about 60° C. and 80° C. respectively, which can then betransported to a hot water system and a heating system (separate flows).The hot water and district heating water in turn heat the supply air to25° C. In industrial applications, this type of configuration could leadto control of several processes just by varying flows according tosuitable algorithms.

FIGS. 5a and 5b show another example of a device for exchange of heatand/or mass transfer of fluids. This device 1′ differs from the device 1in that it is a plate heat exchanger. The first channel layers andsecond channel layers are arranged in channel pairs also in thisexample. In FIG. 5 a, three plates 10 a-10 c are shown forming a channelpair. These three plates are stacked such that between the two plates 10a and 10 b to the left a first fluid flow can be provided and betweenthe two plates 10 b and 10 c to the right a second fluid flow can beprovided. The corner openings form part of fluid inlets and fluidoutlets. The function of the device 1′ is the same as for the device 1,i.e. it enables counter-current or concurrent flows, one flow in thefirst channel layers and one in the second channel layers. The channelpairs are spaced apart from each other, for example by means of spacers8, whereby the cross-current channels 7 are formed therebetween as shownin FIG. 5b where three stacked channel pairs 10 a-c are shown with across-current channel 7 between each channel pair. The spacers 8 may forexample be gaskets.

The channel pairs may share a common plate, so that each channel pair ismade of three plates. Alternatively, the channel pairs may be made offour plates, two forming a first channel layer and two forming a secondchannel layer.

The plates could for example be planar or they could have aturbulence-inducing structure, e.g. a herringbone structure.

The device 1′ could be submersible or immersed in a liquid, in whichcase for example the third flow, through the cross-current channels,could be a convective flow instead of a mechanical flow. Of course, thedevice 1′ does not have to be of the submersible type; all flows couldof course also be mechanical fluid flows.

FIG. 6a shows another aspect of a device for exchange of heat and/ormass transfer. According to this aspect, the device 1″ comprises a firstfluid inlet 17, and a first fluid outlet 19. The device 1″ furthermoreincludes a second fluid inlet 21, and a second fluid outlet 23.

The device 1″ has a plurality of first channel layers connecting thefirst fluid inlet with the first fluid outlet, a plurality of secondchannel layers connecting the second fluid inlet with the second fluidoutlet, and a fluid conduit 25 extending through each of the pluralityof first channel layers and each of the plurality of second channellayers.

The plurality of first channel layers and the plurality of secondchannel layers are arranged in a stacked manner forming stacked fluidchannels. At least some first channel layers are spaced apart fromsecond channel layers, whereby cross-current channels 27 are formedtherebetween, extending from one lateral side of the stacked fluidchannels to the opposite lateral side of the fluid channels, therebyforming lateral fluid inlets between lateral edges of first channellayers and second channel layers and lateral fluid outlets betweenopposite lateral edges of first channel layers and second channellayers. The fluid conduit 25 hence also extends through thecross-current channels 27. This means that the fluid conduit, and thusany fluid flowing therein, will be subjected to also a cross-currentfluid flow in operation.

A cooling fluid or a heating fluid may flow inside the fluid conduit 25,which is thereby heated or cooled by all three fluid flows, flowingthrough the first channel layers, the second channel layers and throughthe cross-current channels 27.

To maximise efficiency, according to one variation each first channellayer is spaced apart from each second channel layer, i.e. there is across-current channel 27 between any first channel layer and secondchannel layer.

Fluid flow into the first channel layers, second channel layers and thecross-current channels 27 may be taken from the same source. To thisend, all fluid flows, except the fluid flow in the fluid conduit 25, maybe taken from one fluid environment, for example from inside a buildingin which the device 1″ is installed or from outside the building.

The device 1″ may be made of a number of stacked sheets as shown in FIG.6 b, or it may alternatively be made of a number of stacked plates,thereby forming a plate heat exchanger.

According to one variation a conduit like fluid conduit 25 may also beprovided through the first channel layers, the second channel layers andthe cross-current channels in the examples shown in FIG. 1 and FIG. 5.

According to one variation the device 1″ only comprises first channellayers, and the first fluid inlet 17, the first fluid outlet 19, whereinthe first channel layers are spaced apart from each other forming thecross-current channels therebetween. The device 1″ would according tothis variation also comprise the fluid conduit 25 extending a pluralityof times through the first channel layers, forming a coil. In this case,there would only be two fluid flows, in addition to the fluid flow inthe fluid conduit 25 in the device 1″, namely the first fluid flow F3and the third fluid flow F1. In this case, the first fluid flow F1 andthe third fluid flow F3 could be flowing simultaneously in the device1″, or they could flow alternatingly; the first fluid flow F1 could forexample first be set to flow through the device 1″ first and in case thefirst channel layers start to freeze, the third fluid flow F3 could beprovided through the device 1″ while the first fluid flow F1 wouldmechanically be set to be stopped. While the third fluid flow F3 isflowing, thus exchanging heat with the fluid conduit 25, the ice in thefirst channel layers would start melting. This operation could berepeated with the first channel layers taking over the heat exchangeprocedure with the fluid conduit 25 if the cross-current channels wouldstart to freeze.

In case of sheets or plates forming the first channel layers and thesecond channel layers, these may be made of impermeable, permeable, orsemi-permeable material. The device may be formed of sheets or platesall having the same properties. All sheets or plates may thus beimpermeable, permeable or semipermeable. Alternatively, the device maycomprise a combination of sheets or plates with different permeabilityproperties. For example a subset of sheets or plates may be permeableand another subset of sheets or plates may be impermeable. Every othersheet or plate may for example be permeable and the remaining sheets maybe impermeable.

The sheets or plates may for example be made of metal, for examplestainless steel, aluminum, copper or any other metal suitable for heattransfer, plastic such as PE, PP, PET, PS, PPS, Polycarbonate, nylon,semi-permeable membranes, for example PEMs like Nafion, or any othersuitable material for heat exchange or mass transfer applications, forexample carbon foam and porous sheets. It is also envisaged that thesheets or plates may comprise a mixture of different materials. In casethe device is a device for energy transfer, in particular if the deviceis a fuel cell, the sheets or plates forming the layers may be made of aceramic material or a mineral material such as perovskite.

The inventive concept has mainly been described above with reference toa few examples. However, as is readily appreciated by a person skilledin the art, other embodiments than the ones disclosed above are equallypossible within the scope of the inventive concept, as defined by theappended claims.

What is claimed:
 1. A device for exchange of energy and/or mass transferbetween fluid flows, which device comprises: a first fluid inlet, afirst fluid outlet, a second fluid inlet, a second fluid outlet, aplurality of first channel layers connecting the first fluid inlet withthe first fluid outlet, and a plurality of second channel layersconnecting the second fluid inlet with the second fluid outlet, whereinthe plurality of first channel layers and the plurality of secondchannel layers are arranged in a stacked manner forming stacked fluidchannels, wherein at least some of the first channel layers are inphysical contact with a respective second channel layer thereby formingchannel pairs, wherein the channel pairs are spaced apart from eachother, whereby cross-current channels are formed therebetween, extendingfrom one lateral side of the stacked fluid channels to the oppositelateral side of the stacked fluid channels thereby forming lateral fluidinlets between lateral edges of first channel layers and second channellayers and lateral fluid outlets between opposite lateral edges of firstchannel layers and second channel layers.
 2. The device as claimed inclaim 1, wherein a cross-current channel arranged between each channelpair.
 3. The device as claimed in claim 1, wherein the cross-sectionalarea of any channel of the first channel layers is greater than across-sectional area of any channel of the second channel layers.
 4. Thedevice as claimed in claim 1, wherein the first fluid inlet and thesecond fluid outlet form a first fluid interface arranged at a first endof the first channel layers and second channel layers.
 5. The device asclaimed in claim 4, wherein the first fluid interface istriangular-shaped in a plane parallel with a first channel layer.
 6. Thedevice as claimed in claim 1, wherein the first fluid outlet and thesecond fluid inlet form a second fluid interface arranged at a secondend of the first channel layers and second channel layers, opposite tothe first end.
 7. The device as claimed in claim 1, wherein each firstchannel layer comprises a plurality of parallel channels and each secondchannel layer comprises a plurality of parallel channels.
 8. The deviceas claimed in claim 9, wherein the parallel channels of the firstchannel layers are arranged in parallel with the parallel channels ofthe second channel layers.
 9. The device as claimed in claim 1, whereinthe first fluid inlet and the second fluid inlet are arranged at a firstend and a second end, respectively, of the stacked fluid channels, thefirst end and the second end being opposite ends of the stacked fluidchannels, and wherein the first fluid outlet is arranged at the secondend and the second fluid outlet is arranged at the first end.
 10. Thedevice as claimed in claim 1, comprising a fluid conduit extendingthrough each of the plurality of first channel layers and each of theplurality of second channel layers.
 11. The device as claimed in claim10, wherein the fluid conduit extends a plurality of times through eachof the plurality of first channel layers and each of the plurality ofsecond channel layers.
 12. The device as claimed in claim 1, whereineach first channel layer is made of two sheets and each second channellayer is made of two sheets, wherein each second channel layer shares asheet with a second channel layer thereby forming the channel pair. 13.The device as claimed in claim 1, wherein the device is a fuel cell. 14.A device for exchange of heat and/or mass transfer between fluid flows,which device comprises: a first fluid inlet, a first fluid outlet, aplurality of first channel layers connecting the first fluid inlet withthe first fluid outlet, the plurality of first channel layers beingarranged in a stacked manner forming stacked fluid channels, and a fluidconduit extending through each of the plurality of first channel layers,wherein at least some first channel layers are spaced apart from eachother, whereby cross-current channels are formed therebetween, extendingfrom one lateral side of the stacked fluid channels to the oppositelateral side of the fluid channels, thereby forming lateral fluid inletsbetween lateral edges of first channel layers and lateral fluid outletsbetween opposite lateral edges of first channel layers, and wherein thefluid conduit extends through each cross-current channel.